Best suggestion I can give is to lie down and relax. Before putting on the audio because it allows the mind to calm down, then play the audio and try not to think, but listen. At first it can be hard so an exercise that worked for me (Not sure about you) if focus on your breathing. Try everyday and eventually it will become a repetition. Also another suggestion I can give is to do the audio when going to bed because it allows the subconscious to accept suggestions more easily. As well as if you had a long and tiring day, then it is easy to not think, but relax.
Not sure if these tips will help, but hope they do!